I think the main issue with all superhero movies is they are all "origin" tales. Just tell a story and quit explaining how Ant-Man learned to shrink. Trust the audience by giving them a great yarn first.

I don't think they will collapse. Movies about novels haven't collapsed have they? Comics are more varied than super hero tales even if they are what I love best. Now do I think the mainstream movie-going audience will go see a movie about an obscure super hero or an angsty hipster? Probably not but it won't make it a bad movie just poor box office contender. Like any medium, the execution of the art will be how it's measured not sales. Crappy movies are crappy movies, regardless of the genre.